Trademark steed of the Final Fantasy JRPG series by Square Enix (formerly Squaresoft).
Large, flightless birds resembling some cross between a chicken and an ostrich or other ratite. Often used as mounts (in the abscence of horses). Primarily yellow, though other colors (and sizes) are known. They make "kweh" and "wark" noises. Baby chocobos are "chicobos" ("ko-chocobos" in Japan).
A chibi version heads up the Final Fantasy Fables/Chocobo series.